1. Field
The present application relates to a hand-held medical handle device having an illumination apparatus with at least one optical semiconductor component as the light source and a method for manufacturing such a medical handle device.
2. Description of Prior Art
A hand-held medical device or medical handle device having an illumination apparatus with a light-emitting diode (LED) is known from the document EP 1,093,765 A2. The illumination apparatus consists of a holder with a U-shaped cross section in which the LEDs are held and are cast in a transparent heat-resistant synthetic resin. The synthetic resin, originally liquid, is cast into the holder, where it undergoes a chemical reaction, causing it to harden and cure, so that the LEDs are sealed off from the environment. Light emission and light conduction are accomplished through the cured synthetic resin. This design should achieve the result that the illumination apparatus can be sterilized in an autoclave.
However, the illumination apparatus of this medical handle device has many disadvantages. One disadvantage is that known synthetic resins suitable for this intended application undergo yellowing after repeated sterilization, so the light transmission and luminous efficiency deteriorate noticeably during the lifetime of the medical handle device. Another disadvantage is that the synthetic resins have a comparatively soft surface. Since the light is emitted through the synthetic resin, it is located at the surface of the illumination apparatus, and thus there is the risk of mechanical damage to the synthetic resin sheathing. Therefore, the release of light by the illumination apparatus is further exacerbated, e.g., due to scratching where the light is refracted or deflected. Furthermore, there is the risk that deep mechanical damage may lead to cracks extending to the LEDs, so that they are no longer protected from water vapor or chemicals, especially during sterilization. The front surface of the resin facing the treatment site may also be designed to be essentially only flat, so that further processing of the emitted light is impossible.
Furthermore, encapsulated LEDs are known from the state of the art, where their casing consists of at least one metallic component, often several metallic components, see, for example, U.S. Pat. No. 4,295,152. These encapsulated LEDs cannot be used in medical handle devices because they do not meet the requirements for electrical safety. If the medical handle devices can be connected to a power source, e.g., if they have an illumination apparatus or are operated with an electric motor, then it is essential to be sure that no electricity is transferred to the user or to the patient during operation or even when a defect occurs. If traditionally encapsulated LEDs having metallized components are used, then to maintain these specifications, defined distances must be stipulated between the electrically conducting metallic outer sheath of the medical handle device and voltage-carrying components such as the encapsulated LED. These defined distances will depend on various factors and amount to at least 0.4 mm (air gap) and/or 0.8 mm (creep zone), for example, in the case of a power supply of 2.8-3.5 V, which is required per LED; in the case of medical handle devices that carry water, e.g., to deliver a spray of water, the distance must be 1.6 mm (air gap) and/or 3.4 mm (creep zone). Since the diameter of the medical handle device is comparatively small at approximately 1-2 cm, it is often impossible to meet these requirements, so that encapsulated LEDs having metal sheaths known in the state of the art cannot be used for medical handle devices.
Therefore, the object is to create a medical handle device having an illumination apparatus that does not have the disadvantages mentioned above. The hand-held device should have in particular an illumination apparatus which guarantees an improved emission of light, preferably as uniform as possible, over the entire lifetime of the hand-held device, which has a surface that can better withstand mechanical damage in particular, which can be sterilized, which allows processing of the light emitted and which fulfills the requirements for electrical safety.
Another disadvantage of the illumination apparatus known from document EP 1,093,765 A2 is the need to make available a separate holder for each illumination apparatus into which the synthetic resin is cast. This is an obstacle in manufacturing the illumination apparatus and increases the manufacturing expense as well as storage and production costs. However, the holder is absolutely necessary because the chemical curing reaction of the synthetic resin takes place very slowly and the holder serves to shape and store the synthetic resin and to hold the LEDs during the liquid phase of the synthetic resin until its final hardening. Since the synthetic resin adheres to the holder, it cannot be released from the cured resin compound or it can be released only at considerable effort, e.g., by first applying a coating to the walls of the holder, so that the holder is usually installed together with or as a part of the illumination apparatus.
Another object is therefore to create a method for manufacturing a mechanical hand-held device having an illumination apparatus and a medical handle device having an illumination apparatus that does not have the disadvantages mentioned above. The hand-held device should have an illumination apparatus which is simpler and less expensive to manufacture, i.e., in particular it should not be necessary to provide a separate holder for each illumination apparatus, into which the optical semiconductor components or LEDs as well as the casting compound encasing them are to be introduced. The hand-held device and the illumination apparatus should also be sterilizable and the light transmission through the illumination apparatus and the light yield should also remain as uniform as possible even after repeated sterilization.